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Abstract: An unwanted yaw motion occurred at the Center of Gravity (CG) of the ... moment occurred due to gun firing impulse at CG of the armored vehicle.
3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

Estimated Disturbance Rejection Feedback Performance of Active Front Wheel Steering for An Armored Vehicle Vimal Rau Aparow1,a, Khisbullah Hudha1,b, Megat Mohamad Hamdan Megat Ahmad1,c and Shohaimi Abdullah1,d Department of Mechanical Engineering, Faculty of Engineering, National Defense University of Malaysia (NDUM), Kem Sungai Besi, 57000 Kuala Lumpur, Malaysia. a

[email protected], [email protected], [email protected], [email protected]

Keywords: Armored vehicle, active front wheel steering, firing disturbance, estimated disturbance rejection feedback, summation of moment.

Abstract: An unwanted yaw motion occurred at the Center of Gravity (CG) of the wheeled armored vehicle caused by the impulse force generated during gun turret firing. The recoil force from the gun fire tends to create instability conditions for the armored vehicle during firing condition and affects the dynamic performance of armored vehicle in lateral direction. In this paper, an active safety system, Active Front Wheel Steering (AFWS) system using estimated disturbance rejection control (EDRF) embodiment is proposed to reject the unwanted yaw disturbance and stabilize the armored vehicle. Besides, the proposed control strategy is also used to re-position the armored vehicle back to its initial position. Therefore, a summation moment reference input is used to counter back the unwanted firing moment occurred due to gun firing impulse at CG of the armored vehicle. The armored vehicle is evaluated in term of yaw rate, yaw angle, vehicle sideslip angle, lateral acceleration and lateral displacement. Significant improvements up to 75% have been achieved by using the proposed control strategy of AFWS system to reject the external disturbance due to the firing force. Introduction Generally, an armored vehicle used a large caliber gun mounted on top of the armored vehicle in order to fire towards the enemies in the battlefield. The firing force from the gun turret creates a large backward momentum which affects the mobility of the armored vehicle. The backward momentum happens at the center of the weapon platform which can produce external disturbance at the center of gravity (COG) of the armored vehicle [1]. Thus, an unwanted yaw motion is generated at the COG of the armored vehicle due to the backward momentum. This momentum creates a lateral force and also the yaw moment at the center of the body gravity of the armored vehicle. This effect causes the vehicle to move out of its intended path. Hence, the armored vehicle loses its directional stability during firing while in dynamic condition. Therefore, most of the armored vehicles have to be in a static position (where the velocity approaches to zero) during a firing condition. The vehicle maintains in this condition to sustain the directional stability of the armored vehicle during the firing condition at the battlefield. However, reducing the velocity can increase the risk of the armored vehicle to be targeted by the enemies for a counterattack [2]. A lot of researches have been developed by the automotive researchers to study on the active safety system for armored vehicle. Previous researchers as in [3-5], focus on the ride and stability system of a wheeled armored vehicle by considering the longitudinal and vertical direction. An armored vehicle with 8 x 8 configurations is used to develop advance active system to reject unwanted disturbance due to road input and gun effect. However, the effect of armored vehicles in lateral direction during gun

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

firing has been neglected eventually in previous studies. The firing impact in lateral direction has been ignored by assuming the armored vehicle performed firing in a static condition, not in a dynamic position. Henceforth, this research investigates on the problem occurred in the wheeled armored vehicle in order to reject the unwanted yaw and lateral motion subjected to the gun disturbance. As a result, an active safety system known as the Active Front Wheel Steering (AWFS) control using an Estimated Disturbance Rejection Feedback (EDRF) is proposed for the armored vehicle. This system is proposed in order to reduce the unwanted yaw motion and also to maintain the directional stability of the armored vehicle after firing by providing correction angle to the steering system. In this study, the AFWS control using EDRF is designed by using the summation moment of the armored vehicle as the reference input for the proposed control strategy of AFWS. The AFWS with EDRF is designed using Matlab SIMULINK and the performance of the proposed control strategy is evaluated using a multi degree freedom of armored vehicle during firing condition. As a result, the proposed control strategy is able to maintain the stability and directional path of the armored vehicle due to firing momentum. This paper organized as follows: The first section represents the introduction and review of some related works. The second section is followed by modeling the dynamic behavior of armored vehicle model using Pacejka Tire Model. The following represent the verification results of the armored vehicle model with CarSim software. The fourth section describes about the AFWS control structure using estimated disturbance rejection feedback with summation of moment as reference. The fifth section discusses the performance of the proposed AFWS control structure for 10 DOF armored vehicle and finally is conclusion. 10 DOF Full Vehicle Model using Pacejka Magic Tire Model A 7 DOF full vehicle model of a wheeled armored vehicle is considered in this study which consists of a single sprung mass (vehicle body) connected to four unsprung masses. The vehicle model is developed by combining the lateral [6] and longitudinal dynamic [7] of a vehicle model. The steering system is modelled using 2 DOF Pitman arm mechanism which is attached with an actuator for AFWS. Power train and brake dynamics are included in this modeling as it contributes in the performance of the vehicle. A single DOF of gun model is included in this study where the gun system is placed on top of the wheeled armored vehicle model behind the COG of the vehicle model and the model is assumed to rotate in the bearing angle direction only. Load Distribution Model. By referring to previous study [7], [8] the load distribution of the vehicle model can be obtained. In this case, the dynamic load distribution is transferred between left and right wheels as the vehicle evaluated in lateral direction. Examining the geometry, two equations formulated in order to describe the front and rear normal forces: 𝑙

β„Ž

β„Ž

𝑙

π‘šπ‘Žπ‘₯ β„Ž

𝑙

2 𝑙 π‘šπ‘Žπ‘₯ β„Ž

𝐹𝑧,𝑓𝑙/π‘Ÿ = [0.5π‘šπ‘” ( π‘‘π‘Ÿ cos πœƒ + 𝑑 sin πœƒ)] Β± [π‘šπ‘Žπ‘¦ ( 𝑑 ) ( 𝑙𝑓 )] – [ 𝑙

β„Ž

β„Ž

𝐹𝑧, π‘Ÿπ‘™/π‘Ÿ = [0.5π‘šπ‘” ( 𝑑𝑓 cos πœƒ + 𝑑 sin πœƒ)] Β± [π‘šπ‘Žπ‘¦ ( 𝑑 ) ( π‘™π‘Ÿ )] + [

2

( )]

(1)

( 𝑙 )]

(2)

Pacejka Tire Model. Several analytical tire models have been developed in order to analyse and simulate the slip/friction characteristics. One of the tire model used is the Pacejka Magic Formula Tire Model [9](Bakker et al., 1989). The Pacejka Tire model is derived mathematically for four tires as bow and the parameters such as B, C, D and E can be obtained from [7] and [9]: πœ‡π‘“π‘–/

π‘Ÿπ‘– (πœ†)

= 𝐷sin [𝐢 arctan(𝐡 Γ— πœ†π‘Ÿπ‘– βˆ’ 𝐸(𝐡 Γ— πœ†π‘Ÿπ‘– βˆ’ arctan(𝐡 Γ— πœ†π‘Ÿπ‘– )))], i=left or right

(3)

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

7 DOF Handling Model. The handling model as shown in Figure 1 mainly describes the performance of armored vehicle along the longitudinal x-axis, the lateral y-axis, and the rotational motion about the vertical z-axis. Therefore, lateral, longitudinal and yaw motions are mainly focused in developing handling model which consists of 3 DOF. The motions are defined as π‘Žπ‘₯ , π‘Žπ‘¦ and π‘ŸΜ‡ respectively. Meanwhile, a single degree of freedom of each tire due to the rotational motion will contribute 4 DOF by the four tires. Hence, a total of 7 DOF will contribute to the performance evaluation of the armored vehicle. 𝐹𝑦 π‘Ÿπ‘™

𝐹𝑦 𝑓𝑙 𝐹π‘₯ π‘Ÿπ‘™

w _

𝐹𝑦 π‘Ÿπ‘Ÿ

𝑣𝑦

πœ‘ π‘™π‘Ÿ 𝐹π‘₯ π‘Ÿπ‘Ÿ

v _ 𝛽

π‘π‘“π‘–π‘Ÿπ‘’ CG

r

𝛿

𝐹π‘₯ 𝑓𝑙

𝑣π‘₯ 𝑙𝑓

πΉπ‘“π‘–π‘Ÿπ‘’

𝐹𝑑 𝐹𝑦 π‘“π‘Ÿ

𝛿

𝐹π‘₯ π‘“π‘Ÿ

Fig. 1: A 7 DOF handling model The motion in the horizontal plane can be characterized by the longitudinal and lateral accelerations, denoted by π‘Žπ‘₯ , and π‘Žπ‘¦ respectively, βˆ‘ 𝐹π‘₯ = 𝐹π‘₯π‘Ÿπ‘Ÿ + 𝐹π‘₯π‘Ÿπ‘™ + [πΉπ‘¦π‘“π‘Ÿ + 𝐹𝑦𝑓𝑙 ] sin 𝛿𝑓 + [𝐹π‘₯π‘“π‘Ÿ + 𝐹π‘₯𝑓𝑙 ] cos 𝛿𝑓 + π‘šπ‘” sin πœƒ - Σ𝐹𝑑 + πΉπ‘“π‘–π‘Ÿπ‘’ cos πœ‘ and, βˆ‘ 𝐹𝑦 = πΉπ‘¦π‘Ÿπ‘Ÿ + πΉπ‘¦π‘Ÿπ‘™ + πΉπ‘¦π‘“π‘Ÿ cos 𝛿𝑓 + 𝐹𝑦𝑓𝑙 cos 𝛿𝑓 - 𝐹π‘₯π‘“π‘Ÿ sin 𝛿𝑓 - 𝐹π‘₯𝑓𝑙 sin 𝛿𝑓 - πΉπ‘“π‘–π‘Ÿπ‘’ sin πœ‘

(4) (5)

The drag force which gives effect of aerodynamics and rolling resistance can be obtained from Aparow et al., (2013). The yaw acceleration, π‘ŸΜˆ , is also dependent on the longitudinal and lateral forces, 𝐹π‘₯ and 𝐹𝑦 which are acting on the each tires: βˆ‘ π‘€π‘¦π‘Žπ‘€ = [𝐹π‘₯π‘Ÿπ‘Ÿ – 𝐹π‘₯π‘Ÿπ‘™ – (πΉπ‘¦π‘“π‘Ÿ – 𝐹𝑦𝑓𝑙 ) sin 𝛿𝑓 – (𝐹π‘₯π‘“π‘Ÿ βˆ’πΉπ‘₯𝑓𝑙 ) cos 𝛿𝑓 ] w/2 + [πΉπ‘¦π‘Ÿπ‘Ÿ + πΉπ‘¦π‘Ÿπ‘™ ]π‘™π‘Ÿ βˆ’ [ (πΉπ‘¦π‘“π‘Ÿ + 𝐹𝑦𝑓𝑙 ) cos 𝛿𝑓 βˆ’ (𝐹π‘₯π‘“π‘Ÿ + 𝐹π‘₯𝑓𝑙 sin 𝛿𝑓 ]𝑙𝑓 + [𝑀𝑧𝑓𝑙 + π‘€π‘§π‘“π‘Ÿ + π‘€π‘§π‘Ÿπ‘™ + π‘€π‘§π‘Ÿπ‘Ÿ ] + πΉπ‘“π‘–π‘Ÿπ‘’ sin πœ‘(π‘π‘“π‘–π‘Ÿπ‘’ ) (6) In order to complete the handling model, the summation of torques acting about each wheel needs to be included. Since the armored vehicle model consists of 4 wheels, 4 DOF is denoted in the handling which is known as equation motion of wheel velocity. πœ”π‘“π‘–/π‘Ÿπ‘– = [πœπ‘’π‘“π‘–,π‘Ÿπ‘– + πœπ‘Ÿπ‘“π‘–,π‘Ÿπ‘– βˆ’ πœπ‘π‘“π‘–,π‘Ÿπ‘– βˆ’ πœπ‘‘π‘“π‘–,π‘Ÿπ‘– (πœ”π‘“π‘–,π‘Ÿπ‘– ) ]⁄𝐽𝑓𝑖,π‘Ÿπ‘–

, i=left or right

(7)

where πœπ‘’π‘“π‘–,π‘Ÿπ‘– are the torques delivered by the engine to each front and rear wheels and πœπ‘π‘“π‘–,π‘Ÿπ‘– are the brake torques applied to each front and rear wheels during braking input. Since this vehicle is a two wheel drive model, the engine torque for the rear wheel is assumed to be zero. The reaction torques, πœπ‘Ÿπ‘“π‘–,π‘Ÿπ‘– are occurred on each front and rear wheels because of tire traction force while viscous friction

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

torque is known as πœπ‘‘π‘“π‘–,π‘Ÿπ‘– . The engine, brake, reaction and viscous friction torques model can be obtained from [9]. Longitudinal and Lateral Slip. The longitudinal and lateral vehicle velocities and can be obtained by the integration of 𝑣π‘₯ and 𝑣𝑦 . They can be used to obtain the side slip angle, denoted by Ξ±. Thus, the slip angle of the front and rear tires are found at 𝛼𝑓𝑙/π‘“π‘Ÿ = tanβˆ’1[(𝑣𝑦 + 𝑙𝑓 π‘ŸΜ‡ )⁄(𝑣π‘₯ + (0.5𝑑)π‘ŸΜ‡ ] βˆ’π›Ώπ‘“ π›Όπ‘Ÿπ‘™/π‘Ÿπ‘Ÿ = tanβˆ’1[(𝑣𝑦 βˆ’ 𝑙𝑓 π‘ŸΜ‡ )⁄(𝑣π‘₯ + (0.5𝑑)π‘ŸΜ‡ ]

(8) (9)

where, 𝛼𝑓 and π›Όπ‘Ÿ are the side slip angles at the front and rear tires respectively. lf and lr are the distance between front and rear tire to the body center of gravity respectively. The longitudinal slip, πœ†, as discussed in [10], described the effective coefficient of force transfer, which is obtained by measuring the difference between the longitudinal velocity of the vehicle, 𝑣π‘₯ , and the rolling speed of the tire, πœ”π‘…, where 𝑅 represents the radius each wheel and πœ”, is the angular velocity of the wheel. Single DOF Gun Firing Model. In order to evaluate the performance of the wheeled armored vehicle due to firing impact, a single degree of gun model was developed in this study. This model is located behind the CG of the armored vehicle and produced external force in the backward direction when firing towards a target. The external force acting at the weapon platform can be formulated using Newton’s law of motion [3]. βˆ‘ πΉπ‘Ÿπ‘’π‘π‘œπ‘–π‘™ = 𝐼𝐻 ⁄𝑑𝐹𝐢

(10)

where, 𝑑 𝐼𝐻 = ∫0 π‘˜ 𝐹𝐻 𝑑𝑑 = (π‘šπ‘ž + (𝛽𝑔 Γ— π‘šπ‘€ ))𝑣0 = (π‘šπ‘ž + ([(700 + 𝑣0 ) Γ— 𝑣0 ] Γ— π‘šπ‘€ ))𝑣0

(11)

𝐼𝐻 is as the impulse of burst force depending on the ballistic properties and 𝑑𝐹𝐢 is defined as the time of functional cycle for each firing. The impulse of burst force is possible to calculate as the integral from the shot beginning to π‘‘π‘˜ shot final time. Meanwhile, π‘£π‘œ Is the initial velocity of the projectile leaves the muzzle, π‘šπ‘ž and π‘šπ‘€ are the mass of projectile and propellant charge while the factor of activity gunpowder gases is known as 𝛽𝑔 [9]. Control Structure of AFWS using 10 DOF armored vehicle model Referring to previous research works, this study has proposed a new control strategy of AFWS control using two types of control loop known as outer and inner loop. The outer loop mainly designed by using and a summation of the moment (as the reference input) and Estimated Disturbance Rejection Feedback (SuM-EDRF) embodiment while the inner loop is the Pitman arm steering actuator system. Outer loop control of AFWS Estimated Disturbance Rejection Feedback of Active Front Wheel Steering. The output from the wheeled armored vehicle model is measured analytically in terms of lateral acceleration, π‘Žπ‘¦ π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ and also yaw rate, π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ due to dynamic motion. Both yaw rate and lateral accelerations are feedback to EDRF embodiment to estimate the firing moment and yaw rate due to firing impulse. The lateral force, 𝐹𝑦 , is assumed to be proportional to the yaw rate, π›ΉΜ‡π‘“π‘–π‘Ÿπ‘–π‘›π‘” of the armored vehicle in order to estimate the yaw rate of the armored vehicle due to firing impact. Likewise, the response of yaw rate, π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ from wheeled armored vehicle is assumed to be proportional to the firing moment,

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

𝑀𝑓_π‘’π‘ π‘‘π‘–π‘šπ‘Žπ‘‘π‘’

acting on armored vehicle during firing condition. Based on this assumption, second order of polynomial equation is developed for both conditions which are: π‘˜π‘¦π‘“π‘–π‘Ÿπ‘–π‘›π‘”

u and, π‘˜π‘€π‘“π‘–π‘Ÿπ‘–π‘›π‘”

u

= 𝐢1 𝑒2 + 𝐢2 𝑒1 + 𝐢3 = 𝐹𝑦

(12) (13)

= 𝐢4 𝑒2 + 𝐢5 𝑒1 + 𝐢6 = π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘

(14) (15)

where 𝐢1 , 𝐢2 , 𝐢3 , 𝐢4 , 𝐢5 , 𝐢6 are the constant parameters are obtained by running several experimental trials, and graphing a plot of a measure of firing moment against a measure of actual yaw rate. Hence, the estimated yaw rate and moment due to firing are formulated as: πœ³Μ‡π’‡_π’†π’”π’•π’Šπ’Žπ’‚π’•π’† = π›ΉΜ‡πΉπ‘–π‘Ÿπ‘–π‘›π‘” + π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ = (π‘˜π‘¦π‘“π‘–π‘Ÿπ‘–π‘›π‘” Γ— 𝐹𝑦 ) + π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ 𝑴𝒇_π’†π’”π’•π’Šπ’Žπ’‚π’•π’† = π‘˜π‘€π‘“π‘–π‘Ÿπ‘–π‘›π‘” Γ— π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘

(16) (17)

Summation of Moment as Desired Input. The summation of moment embodiment is proposed to enhance the performance of AFWS due to external firing disturbance by adding skyhook control mechanism which acts in lateral direction. This mechanism is developed by creating fictitious linear damper at the front and rear of the armored vehicle while fictitious rotary damper at the CG of the armored vehicle. The fictitious damper connects the armored vehicle to an imaginary lateral wall as shown in Figure 2. This method is used in a way of suppressing unwanted moment and yaw motion of the armored vehicle due to external disturbance of firing force. The algorithm of the desired moment, π‘€π‘‘π‘’π‘ π‘–π‘Ÿπ‘’π‘‘ is given as follows:: βˆ‘ π‘€π‘‘π‘’π‘ π‘–π‘Ÿπ‘’π‘‘ = π‘€π‘ π‘˜π‘¦_𝑓 + π‘€π‘ π‘˜π‘¦_π‘Ÿ + π‘€π‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘

(18)

where π‘€π‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘ , π‘€π‘ π‘˜π‘¦_𝑓 and π‘€π‘ π‘˜π‘¦_π‘Ÿ are defned as π‘€π‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘ = πΆπ‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘ Γ— 𝛹̇ π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ π‘€π‘ π‘˜π‘¦_𝑓 = πΉπ‘ π‘˜π‘¦_𝑓 Γ— 𝑙𝑓 = (πΆπ‘ π‘˜π‘¦_𝑓 Γ— 𝑉𝑦𝑓 ) π‘€π‘ π‘˜π‘¦_π‘Ÿ = πΉπ‘ π‘˜π‘¦_π‘Ÿ Γ— π‘™π‘Ÿ = (πΆπ‘ π‘˜π‘¦_π‘Ÿ Γ— π‘‰π‘¦π‘Ÿ )

(19) (20)

and 𝑉𝑦𝑓 = ∫ π‘Žπ‘¦π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ – [ π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ Γ— 𝑙𝑓 ] 𝑉𝑦 = ∫ π‘Žπ‘¦ + [ π›ΉΜ‡π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘ Γ— π‘™π‘Ÿ ]

(21)

(22) The term 𝑉𝑦𝑓 and π‘‰π‘¦π‘Ÿ are the front and rear vehicle lateral velocities due to lateral acceleration at center of gravity of armored vehicle. Meanwhile, 𝑙𝑓 and π‘™π‘Ÿ are the front and rear distance from center of gravity of the armored vehicle. The front and rear lateral damper forces are defined as πΆπ‘ π‘˜π‘¦_π‘“π‘Ÿπ‘œπ‘›π‘‘ and πΆπ‘ π‘˜π‘¦_π‘Ÿπ‘’π‘Žπ‘Ÿ and rotational damper is defined as πΆπ‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘ . π‘Ÿ

π‘‘π‘¦π‘›π‘Žπ‘šπ‘–π‘

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

πΉπ‘“π‘Ÿπ‘œπ‘›π‘‘

𝑉π‘₯

πΆπ‘ π‘˜π‘¦_π‘“π‘Ÿπ‘œπ‘›π‘‘

𝑙𝑓 𝐢𝐺

π‘ŸΜ‡

πΆπ‘ π‘˜π‘¦_π‘Ÿπ‘œπ‘‘

𝑉𝑦

π‘™π‘Ÿ

Skyhook Imaginary wall

πΆπ‘ π‘˜π‘¦_π‘Ÿπ‘’π‘Žπ‘Ÿ πΉπ‘Ÿπ‘’π‘Žπ‘Ÿ

Fig. 2: Wheeled armored vehicle with imaginary skyhook wall and dampers Inner loop control of AFWS The inner loop model consists of Pitman arm steering and DC motor model. The DC motor model is used as an actuator to provide correction to the steering model in order to control the wheel angle during firing moment. The detailed explanation on Pitman arm steering and actuator model can be obtained from [9] and [10]. Figure 3 shows the inner loop model using Pitman arm steering and DC motor model. From controller PID 2

+ -

PID 3

+ -

PID 4

Steering angle DC Motor

Voltage

Steering Wheel angle angle Pitman Arm Steering

Armored vehicle

Fig. 3: Inner loop model of AFWS Proposed AFWS Control Structure. An AFWS control structure has been proposed based on the equations derived in sections 2 and 3 as shown in Figure 4. The control structure is developed based on combination of both outer and inner loop controls. The additional embodiment of estimated disturbance rejection feedback with a summation of moment as reference (SuM-EDRF) of the AFWS control has been included in the control design. Summation of Moment Yaw Rate Firing Lateral moment acceleration

+

PID 1

-

+

Inner Loop Model PID 2

Armored vehicle model

Wheel angle

Wheel angle

Powertain

Engine torque

Gun System Model

Firing force

-

Estimated Yaw Rate

Yaw Rate Lateral acceleration

Lateral acceleration

Rate Estimated Firing Moment

Yaw Rate

Estimated Disturbance Rejection Feedback Control

Fig. 4: AFWS of wheeled armored vehicle using SuM-EDRF Performance Evaluation of AFWS with EDRF for Armored Vehicle

This section describes simulation results on the performance of an active safety system based AFWS control strategy for the 10 DOF armored vehicle during firing condition. The performance of an armored vehicle is evaluated using passive and active safety system using PID controllers with two conditions which are by using estimated disturbance rejection feedback with summation of moment

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

reference (SuM-EDRF) embodiment and a system without implementing this embodiment. The purpose of this condition is to investigate the effectiveness of the additional EDRF with summation of moment embodiment to improve the performance of armored vehicle compared with basic AFWS control structure. The armored vehicle is evaluated in term of yaw rate, yaw angle, lateral acceleration and lateral displacement due to the firing effect. The simulation was performed for a period of 10 seconds and tested using Runge-Kutta solver with a fixed step size 0.01s. The external disturbance from gun weapon platform is used to introduce firing force up to 40 kN by using 75mm caliber at 90Β° of firing angle. The performance comparison of AFWS with the passive armored vehicle model is shown in Figures 5 to 8. Yaw angle against time 0.02

AFWS without SuM-YFME AFWS with SuM-YFME Passive

0.05

Yaw angle, rad

Yaw rate, rad/s

Yaw rate against time

0 -0.05 -0.1 0

2

4

6

8

10

time,t

0

-0.02

-0.04 0

2

Fig 5: Yaw rate against time

Fig 6: Yaw angle against time Lateral displacement against time

AFWS without SuM-YFME AFWS with SuM-YFME Passive

1 0.5 0 -0.5 0

2

4

6

8

time, t

Fig. 7: Lateral acceleration against time

10

1.5 Lateral displacement, m

Lateral acceleration, m/s2

Lateral acceleration against time 1.5

4

AFWS without SuM-YFME AFWS with SuM-YFME Passive 6 8 10 time, t

AFWS without YFME AFWS with YFME Passive

1

0.5

0 0

2

4

6

8

10

time, t

Fig. 8: Lateral displacement against time

Based on the results above, the AFWS control strategy using estimated disturbance rejection feedback with summation of reference embodiment able to reduce the yaw motion and lateral displacement of the armored vehicle after firing impulse. According to Fig. 5 and 8, the AFWS control strategy able to reduce yaw rate up to 80 % and yaw angle up to 60 % from the passive armored vehicle model compared to AFWS control strategy without the additional embodiment. Whereas, the distance travelled by the armored vehicle in the lateral direction reduced after the 3rd second and the vehicle able to return back to initial traveling position (lateral displacement = 0.05 m). Conclusion As a conclusion, an AFWS control strategy can be used for the 10 DOF armored vehicle in a lateral direction. AFWS control strategy using estimated disturbance rejection feedback with summation of reference embodiment able to improve the dynamic performance of the armored vehicle during firing condition. The proposed control strategy able to stabilize the armored vehicle from the firing impact and at same time, reposition back the armored vehicle back to its initial travelling path. Thus, the proposed AFWS control strategy significantly increases the dynamic performance of the armored vehicle even with external disturbance due to firing force.

3rd International Conference on Recent Advances in Automotive Engineering & Mobility Research December 1-3, 2015, Melaka, Malaysia 014-ReCAR2015

Acknowledgement This work is part of the research project entitled β€œRobust Stabilization of Armored Vehicle Firing Dynamic Using Active Front Wheel Steering System”. This research is fully supported by LRGS grant (No. LRGS/B-U/2013/UPNM/DEFENSE & SECURITY – P1) lead by Associate Professor Dr. Khisbullah Hudha. The authors would like to thank the Malaysian Ministry of Science, Technology and Innovation (MOSTI) and Universiti Pertahanan Nasional Malaysia for their continuous support in the research study. This financial support is gratefully acknowledged. References [1] T. C. Yean, M. S. Hong and V. Yew, Fighting Vehicle Technology, DSTA Horizons, 2013, pp. 62-77. [2] K. Hudha, V. R. Aparow, M. Murad, S. A. F. Ishak, Z. A. Kadir, N. H. Amer and M. L. H. A. Rahman. Yaw Stability Control System, Malaysia Patent, Filed on 14 October 2014. PI 2015700778. (Pending). [3] K. Hudha, H. Jamaluddin and P. M. Samin, Disturbance rejection control of a light armoured vehicle using stability augmentation based active suspension system, International Journal of Heavy Vehicle Systems. 2008, 15 (2), 152-169. [4] J. Tvarozek and M. Gullerova, Increasing Firing Accuracy of 2A46 Tank Cannon Built-in T-72 MBT, American International Journal of Contemporary Research, 2012, (2)9, USA. [5] M. W. Trikande, V. V. Jagirdar and M. Sujithkumar, Modelling and Comparison of Semi-Active Control Logics for Suspension System of 8x8 Armoured Multi-Role Military Vehicle, Applied Mechanics and Materials, 2014, 592, 2165-2178. [6] K. Hudha, Z. A. Kadir and H. Jamaluddin, Simulation and experimental evaluations on the performance of pneumatically actuated active roll control suspension system for improving vehicle lateral dynamics performance, International Journal of Vehicle Design. 2014, 64(1), 72100. [7] M. Short, M. J. Pont, and Q. Huang, Safety and reliability of distributed embedded s ystems simulation of vehicle longitudinal dynamics, Embedded Systems Laboratory Technicial Report, ESL 04-01, 2004, Univercity of Leicester, Leicester. [8] E. Bakker, L. Nyborg and H. B. Pacejka, Tyre modelling for use in vehicle dynamics studies, 1987, No. 870421, SAE Technical Paper. [9] V. R. Aparow, K. Hudha, M. M. Hamdan and S. Abdullah, (2015). Study on the Dynamic Performance of Armored Vehicle in Lateral Direction due to Firing Impact. Journal of Advances in Military Technology. Accepted. [10] V. R. Aparow, K. Hudha, F. Ahmad, and H. Jamaluddin, Model-in-the-loop simulation of gap and torque tracking control using electronic wedge brake actuator, International Journal of Vehicle Safety. 2014, 7(3), 390-408.